Disease and/or trauma cause deterioration of natural joints of the human body. Replacement of natural joints with joint prostheses can distinctly enhance the quality of life of an individual affected by such joint conditions. Various joint prostheses are known. Among the more common joint prostheses are those that replace all or part of the natural knee and hip joints.
Components of joint prostheses must be implanted and secured within existing bone. In the case of hip arthroplasty, a surgical technique in which the hip joint is replaced by a prosthetic joint, a cavity is prepared in a proximal portion of the patient's femur to receive a femoral stem, a portion of a prosthetic hip joint. Other joint replacement surgical techniques require the formation of similar cavities within existing bone for the installation of various prosthesis components.
Once such a cavity is prepared, the prosthesis component may be secured within the cavity by a number of techniques. For example, the prosthesis component may be cemented within the cavity, or it can be installed through mechanical fixation by a friction fit or the use of a fixation device.
Yet another technique, known as "hybrid fixation," uses cement to secure a portion of a component in place, whereas other portions of the component are secured by directly mating with the bone or other methods of securement. This technique can be particularly challenging, however, as cement must be confined to a selected portion of the component, avoiding the non-cemented surfaces, yet be applied in sufficient abundance to create a void-free cement mantle. The difficulty is even greater when the portion to be cemented is bounded by non-cemented surfaces.
Although techniques exist to combine cement-based and cement-free fixation of bone prosthesis components within bone, it is desirable to provide additional techniques that can be easily implemented and that address the challenges presented by hybrid fixation.